NSMutableArray *commentListArray=[[NSMutableArray alloca]init];

// 为每个属性创建NSSortDescriptor对象,并确定为升序

NSSortDescriptor *sortDescriptor = [[NSSortDescriptor alloc] initWithKey:@"commentId" ascending:YES];//

// 设置排序优先级，并组成数组。这里优先级最高为commentId

NSArray * sortDescriptors =  [[NSArray alloc] initWithObjects:&sortDescriptor count:1];

[commentListArray sortUsingDescriptors:sortDescriptors];

// 为数组中每个元素执行方法，输出状态

[commentListArray makeObjectsPerformSelector:@selector(printState)];